I am really concerned for my younger brother and need some advice on how to handle this situation. He is 22 and has been with his gf since he was 19 (they met at university and she is the same age as him.) After they graduated, they stayed in their uni town and moved into a rented flat together. I have always been very close to him and I am worried that things aren't right in his relationship.
We spent the weekend together as it was our dad's birthday and we were all at my parents' house. We got chatting about how things were going and I noticed some nasty bruises on his upper arm (he had been wearing a cardigan but took it off because of the hot weather and you could see it below the arm of his t shirt.) I asked him how he got them and he said he wasn't sure, must have done it without realising... but he seemed a bit shifty. I'm not sure if I believe him.
Later on in the afternoon, I was asking him about his new job and he was saying he went out with his friends to celebrate. He mentioned that he'd come back to the flat late and his gf had been upset and they'd had a row. He said she'd thrown a wine glass against the wall in temper and he'd been shocked because it started over this night out (which she had been invited to but declined as she had plans with friends. Except she then stayed in and didn't go out at all, saying she was ill!) He said she didn't trust him with a woman from work and was accusing him of cheating. I know he would never cheat. He adores this girl and he's not like that anyway.
He has always been a quiet, creative type, not massively outgoing but he is more of a thinker than a talker. His gf seemed a nice girl at first but she is very different from him - confident, ambitious, not afraid to say what she thinks etc. She wants to be a model and talks about that a lot. I find her quite manipulative - she always seems to get her own way with things and he has missed family events because she wasn't happy with going. I'm not happy with the way she speaks to him sometimes either - telling him she doesn't like his clothes and he should have worn something else, etc. I know from what he's told me that she's had a tough time at home. Her mum has manic depression and there was violence at home when she was younger. My brother seems to forgive her anything because of this. I thin she leans on him emotionally and I suspect she pressured him to move in with her.
I'm just so worried about him because I don't think these bruises are right. I'm wondering if he's being abused and is embarrassed to say because domestic abuse is usually associated with females. He has become even more quiet and withdrawn than usual lately. He used to be a happier but he seemed down at the party today. But maybe I am making something out of nothing? I just think that throwing a wine glass in temper isn't normal in a secure relationship. What do you think I should do?